The purpose of this study is to evaluate how patients absorb their antituberculosis drugs and how long it takes for their bodies to eliminate the drugs. We will look to see if other patient characteristics such as age, weight, gender or other medical conditions affect how their bodies handle the drugs. This information will be used to help other TB doctors dose patients with certain conditions, such as patients with kidney disease, liver disease, AIDS or diabetes, who may differ from the general population. The results of the assays are analyzed by investigators at National Jewish Center. The data are then described at meetings and in medical journals to help other TB workers treat their patients. After the study is explained to the patients, they can decide whether or not they want to participate. If they want to participate, they take their prescribed antituberculosis medications as usual. On the days of blood draws, a health care worker records the exact times of the doses. Then, a series of carefully timed blood samples are collected through an intravenous catheter. These samples are then tested for the amount of drug present using assays developed at National Jewish Medical and Research Center.